Earsonics ONYX Review

Earsonics Onyx

I first became familiar with Earsonics when I reviewed the Grace Platnium some time ago. They instantly became a brand to look out for, as I thought the Grace Platnium was one of the best high-end IEMs you can get, rivaling some of the more prestige models in its price range. The ONYX is their more mid-fi option in their limited library of products, and I have been able to test it out to see where it stands. There have been a good number of IEMs in this price range that have impressed me, and the ONYX has some good chances considering the quality I heard on the Grace Platnium. Is it worth it for $639?

Earsonics items

What You Get

  • 4C-HR Cable
  • Comply foam tips
  • Silicone tips
  • Silicon bi-flange tips
  • Carrying case
  • Cleaning Tool
  • User manual

Earsonics single

Look and Feel

Each IEM from Earsonics carries the exact same design with just differences in color and material. It is a solid aesthetic, and I don’t see the need for Earsonics to change it up when they have such a winning build already. There’s a rigidity to the design, but the housing seems the perfect size for the style it possesses. Speaking of style, the all-black shell is simple and classy for an IEM and just the feel of the casing is smooth. In the ear, the ONYX feels light and natural while sitting in your concha. No fatigue could be felt long-term.

Earsonics cable


The ONYX is a hybrid system that utilizes four transducers with a 3-way HQ filter complete with impedance correction.

  • Sensitivity: 122dB/mW
  • Frequency response: 10 Hz -20 kHz
  • Impedance: 16.5 ohms

Earsonics pair


My only reference for what Earsonics is capable of in their soundstage region is from the Grace Platnium, and of course, you really can’t compare the two since they exist in wildly different price ranges. However, the Onyx at only $639 accomplishes a lot in its spatial properties, so much so that the soundstage and imaging of both IEMs can be comparable. It consists of an extensive width that reaches past the earphone’s outer shell and keeps the fullness of the image intact. I would describe the overall appearance of this stage as a semi-holographic oval, with height extension a bit more average than how deep the sound signature can go.

Some of its depth actually took me by surprise, with the track “Lost In Thought” by GoGo Penguin giving me what this soundstage can really do. There’s an ambient, low-end wind effect that travels across the mix, and it felt like it was getting underneath me. This complements the overall darker profile of the sound signature, but I was happy with how the ONYX can add more theatricality to its delivery of the stereo field. Dimensionally, the ONYX is definitely a success for me, as this IEM is able to accurately portray its spatial imaging with finesse, as well as a good sense of wrap-around for enhanced immersion.

Low End

I touched on a bit of the low-end signature by describing it as a darker timbre, and while I think that’s true it doesn’t mean that the ONYX has a cloudy resonance. I feel that way with some darkly tuned IEMs, but in the case of the ONYX, the bass can be dark and dominant while also being incredibly sharp. Even with their enveloping fullness, the bass frequencies have a good amount of separation to them so that their content is able to exaggerate what it wants to without muddying the clarity in the rest of the sound spectrum. If you’re looking for some substantial sub-bass boost and texture, then the ONYX will deliver it in droves.


The ONYX keeps up the energy well into the midrange, where instruments and vocals are able to pop. Sound elements have some significant meat on their bones, forming a warm but rich presentation of sound elements. Vocals push themselves forward and really cut through a mix, while the instrumentals surrounding each track spatially differentiate themselves from one another, resulting in a cleaner definition. I found that male vocals in particular have a significant vibration to them, accentuating the details of certain performances. The best example I found in my testing was on the track “Hold The Line” by Alex Cameron, where the low-mid frequencies were able to add a subtle gravelly texture to his voice.


For a significantly bottom-heavy sound signature, the treble region doesn’t feel lacking in any way. It may not match the liveliness of the lows and mids, but it helps balance the sound signature in some necessary instances. There’s not as much volume to the frequencies, but it still retains a consistent shape that makes the rest of the frequency response feel complete. This is the most neutral the timbre of the ONYX gets, and it works to great effect, offering detail and crispness when needed.


With the ONYX, Earsonics have a fantastic mid-budget IEM that brings some heavy competition to the market. A spacious soundstage and aggressive bass timbre help the ONYX exceed their range and set their own standards for sound quality. The treble won’t turn any heads, but some won’t take issue with its more neutral tuning. Add on a natural fit and a fine cable, and the ONYX becomes a must-have item.

ProsĀ  Cons
  • Spacious soundstage
  • Semi-holographic imaging
  • Deep bass
  • Rich mids
  • Good fit
  • Great build
  • Less energetic treble

The Earsonics ONYX is available at Audio46.

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Alex S. is a sound designer and voice-over artist who has worked in film, commercials, and podcasts. He loves horror movies and emo music.